You Tomoe
You is a half French half Japanese. His French name is Henri Samuel Jean Aimée. Likewise, he is half-French and was often teased for that as a kid. Tsukiko was his first friend because she didn’t make fun of him for being a half Japanese half French as the other children did, he is also her childhood friend but since he transferred to France she didn’t remember, he asked his parents if he could spend some time with her transferring to her school in Japan.
At first You basically just wants her all to himself and he constantly fights with Kanata about it. Later You realizes the importance of having friends and becomes part of their little group. He’s the first one to admit his feelings to Tsukiko, and in general he’s pretty straight forward to the point to hug her and kiss her the first day he transfers.
Later on he tells her his feelings again and asks her to answer him after it’s been decided that he’s going back to France at the end of May. Tsukiko immediately decides that she likes him and ends up being his girlfriend.
Five years have passed since You moved back to France, and comes back to Tsukiko to get married.